‘ And the children of Reuben, and the children of Gad, and the half tribe of Manasseh, returned, and departed from the children of Israel out of Shiloh, which is in the land of Canaan, to go to the land of Gilead, to the land of their possession, of which they were possessed according to the commandment of YHWH by the hand of Moses.'
So no doubt with great joy and expectation the three Transjordan contingents returned to their homes in Transjordan. Here ‘the land of Gilead' indicated loosely the whole area controlled by the three tribes. Gilead was split into two parts by the great trench of the Jabbok, one half had been ruled by Sihon the other by Og. The name Gilead is used in various ways. Sometimes it refers to the section possessed by Reuben known as ‘half Gilead' (Joshua 12:2; Joshua 12:5; Numbers 32:1; Numbers 32:29), at other times to the northern section (Joshua 17:1; Joshua 17:5; Deuteronomy 2:36; Deuteronomy 3:15-16), and often to the whole area between the Yarmuk, south east of the Sea of Chinneroth (Galilee), and the Arnon (1 Kings 4:19; 2 Kings 10:33), The whole area is often described as ‘all Gilead' (Deuteronomy 3:10; 2 Kings 10:33).
We do not know exactly when this was, but must presume it was not long after Joshua 11:23. These three tribes would have little need to be directly involved in the activities of the individual tribes, nor in the distribution of the land. Their allotments had been given to them by Moses (Joshua 13:8-31). But their presence would be required while the initial bridgehead was being established.
This ties in with the fact that it was seemingly while the tribes were gathered at Shiloh, which must therefore come after Joshua 14:6 when they were still at their base camp at Gilgal. Thus they witnessed the initial movement of Judah to take the hill country under Joshua's overall command, and the movement of Ephraim and Manasseh to establish themselves in the hill country of Ephraim. Until that was done there was no bridgehead. So it was probably around the time of Joshua 18:1 when the official establishment of the camp at Shiloh took place, and it was made the central sanctuary. Such a movement from Gilgal to Shiloh would anyway make Transjordan more vulnerable to outside attack. While they were encamped at Gilgal it was a reminder to enemies across the Jordan that any indication of hostile intent could be met by force.
“Of which they were possessed according to the commandment of YHWH by the hand of Moses.” It is again stressed that their settlement Beyond Jordan eastward was at the behest of YHWH (Numbers 32:1), for there was a strong feeling among many that it was ‘outside the land of the possession of YHWH' (Joshua 22:19).