John Gill Commentary Exodus 4:29

"And Moses and Aaron went and gathered together all the elders of the children of Israel:" — Exodus 4:29 (ASV)

And Moses and Aaron went
Set forward for Egypt: and being come thither,

gathered together all the elders of the children of Israel ;
the heads of tribes and families, as many as they could conveniently get together in one place; probably in the metropolis of the kingdom, where Pharaoh's palace was, since we quickly hear of their going in to him.