John Gill Commentary Numbers 6:15

"and a basket of unleavened bread, cakes of fine flour mingled with oil, and unleavened wafers anointed with oil, and their meal-offering, and their drink-offerings." — Numbers 6:15 (ASV)

And a basket of unleavened bread
As at the consecration of Aaron and his sons, (Exodus 29:2) ; though for peace offerings for thanksgiving leavened bread was offered, (Leviticus 7:13) ;

cakes of fine flour mingled with oil, and wafers of unleavened bread
anointed with oil ;
ten of each sort, as Jarchi says, ten cakes and ten wafers, see (Exodus 29:9) (Leviticus 7:12) ;

and their meat offering and their drink offering ;
which always used to attend every sacrifice.