I really love this story...

Joshua 22
1 Then Joshua summoned the Reubenites and the Gadites and the half-tribe of Manasseh, 2 and said to them, "You have kept all that Moses the servant of the LORD commanded you, and have listened to my voice in all that I commanded you. 3 "You have not forsaken your brothers these many days to this day, but have kept the charge of the commandment of the LORD your God. 4 "And now the LORD your God has given rest to your brothers, as He spoke to them; therefore turn now and go to your tents, to the land of your possession, which Moses the servant of the LORD gave you beyond the Jordan. 5 "Only be very careful to observe the commandment and the law which Moses the servant of the LORD commanded you, to love the LORD your God and walk in all His ways and keep His commandments and hold fast to Him and serve Him with all your heart and with all your soul." 6 So Joshua blessed them and sent them away, and they went to their tents. 7 Now to the one half-tribe of Manasseh Moses had given {a possession} in Bashan, but to the other half Joshua gave {a possession} among their brothers westward beyond the Jordan. So when Joshua sent them away to their tents, he blessed them, 8 and said to them, "Return to your tents with great riches and with very much livestock, with silver, gold, bronze, iron, and with very many clothes; divide the spoil of your enemies with your brothers." 9 The sons of Reuben and the sons of Gad and the half-tribe of Manasseh returned {home} and departed from the sons of Israel at Shiloh which is in the land of Canaan, to go to the land of Gilead, to the land of their possession which they had possessed, according to the command of the LORD through Moses.
10 When they came to the region of the Jordan which is in the land of Canaan, the sons of Reuben and the sons of Gad and the half-tribe of Manasseh built an altar there by the Jordan, a large altar in appearance. 11 And the sons of Israel heard {it} said, "Behold, the sons of Reuben and the sons of Gad and the half-tribe of Manasseh have built an altar at the frontier of the land of Canaan, in the region of the Jordan, on the side {belonging to} the sons of Israel." 12 When the sons of Israel heard {of it,} the whole congregation of the sons of Israel gathered themselves at Shiloh to go up against them in war. 13 Then the sons of Israel sent to the sons of Reuben and to the sons of Gad and to the half-tribe of Manasseh, into the land of Gilead, Phinehas the son of Eleazar the priest, 14 and with him ten chiefs, one chief for each father's household from each of the tribes of Israel; and each one of them {was} the head of his father's household among the thousands of Israel. 15 They came to the sons of Reuben and to the sons of Gad and to the half-tribe of Manasseh, to the land of Gilead, and they spoke with them saying, 16 "Thus says the whole congregation of the LORD, 'What is this unfaithful act which you have committed against the God of Israel, turning away from following the LORD this day, by building yourselves an altar, to rebel against the LORD this day? 17 'Is not the iniquity of Peor enough for us, from which we have not cleansed ourselves to this day, although a plague came on the congregation of the LORD, 18 that you must turn away this day from following the LORD? If you rebel against the LORD today, He will be angry with the whole congregation of Israel tomorrow. 19 'If, however, the land of your possession is unclean, then cross into the land of the possession of the LORD, where the LORD'S tabernacle stands, and take possession among us. Only do not rebel against the LORD, or rebel against us by building an altar for yourselves, besides the altar of the LORD our God. 20 'Did not Achan the son of Zerah act unfaithfully in the things under the ban, and wrath fall on all the congregation of Israel? And that man did not perish alone in his iniquity.' "
21 Then the sons of Reuben and the sons of Gad and the half-tribe of Manasseh answered and spoke to the heads of the families of Israel. 22 "The Mighty One, God, the LORD, the Mighty One, God, the LORD! He knows, and may Israel itself know. If {it was} in rebellion, or if in an unfaithful act against the LORD do not save us this day! 23 "If we have built us an altar to turn away from following the LORD, or if to offer a burnt offering or grain offering on it, or if to offer sacrifices of peace offerings on it, may the LORD Himself require it. 24 "But truly we have done this out of concern, for a reason, saying, 'In time to come your sons may say to our sons, "What have you to do with the LORD, the God of Israel? 25 "For the LORD has made the Jordan a border between us and you, {you} sons of Reuben and sons of Gad; you have no portion in the LORD." So your sons may make our sons stop fearing the LORD.' 26 "Therefore we said, 'Let us build an altar, not for burnt offering or for sacrifice; 27 rather it shall be a witness between us and you and between our generations after us, that we are to perform the service of the LORD before Him with our burnt offerings, and with our sacrifices and with our peace offerings, so that your sons will not say to our sons in time to come, "You have no portion in the LORD.'" 28 "Therefore we said, 'It shall also come about if they say {this} to us or to our generations in time to come, then we shall say, "See the copy of the altar of the LORD which our fathers made, not for burnt offering or for sacrifice; rather it is a witness between us and you.'" 29 "Far be it from us that we should rebel against the LORD and turn away from following the LORD this day, by building an altar for burnt offering, for grain offering or for sacrifice, besides the altar of the LORD our God which is before His tabernacle."
30 So when Phinehas the priest and the leaders of the congregation, even the heads of the families of Israel who {were} with him, heard the words which the sons of Reuben and the sons of Gad and the sons of Manasseh spoke, it pleased them. 31 And Phinehas the son of Eleazar the priest said to the sons of Reuben and to the sons of Gad and to the sons of Manasseh, "Today we know that the LORD is in our midst, because you have not committed this unfaithful act against the LORD; now you have delivered the sons of Israel from the hand of the LORD." 32 Then Phinehas the son of Eleazar the priest and the leaders returned from the sons of Reuben and from the sons of Gad, from the land of Gilead to the land of Canaan, to the sons of Israel, and brought back word to them. 33 The word pleased the sons of Israel, and the sons of Israel blessed God; and they did not speak of going up against them in war to destroy the land in which the sons of Reuben and the sons of Gad were living. 34 The sons of Reuben and the sons of Gad called the altar {Witness;} "For," {they said,} "it is a witness between us that the LORD is God."