John Gill Commentary Leviticus 8:29

"And Moses took the breast, and waved it for a wave-offering before Jehovah: it was Moses` portion of the ram of consecration; as Jehovah commanded Moses." — Leviticus 8:29 (ASV)

And Moses took the breast
Of the ram of consecration:

and waved it for a wave offering before the Lord ;
this Moses seems to have waved with his own hands, and not upon the hands of Aaron and his sons, putting his under them, as in the wave offering of the fat, shoulder, and cakes, and for which the following words seem to give a reason:

[for] of the ram of consecration it was Moses's part ;
the breast of it was his:

as the Lord commanded Moses ;
see (Exodus 29:26) .