The bones of Joseph, and the other patriarchs, as appears from Acts 7:16. The oath was taken only by the parents, but because the matter of it was not personal, and of particular concernment to them, but common to them and their children, therefore it obliged both the parents and their children, as Moses here signifieth.
Related Commentaries of Exodus 13:19
Exodus 13:19
19 And Moses took the bones of Joseph with him: for he had straitly sworn the children of Israel, saying, God will surely visit you; and ye shall carry up my bones away hence with you.