John Gill Commentary Exodus 1:22

"And Pharaoh charged all his people, saying, Every son that is born ye shall cast into the river, and every daughter ye shall save alive." — Exodus 1:22 (ASV)

And Pharaoh charged all his people
Finding he could not carry his point with the midwives, he gave a general order to all his people everywhere:

saying, every son that is born you shall cast into the river ;
the river Nile; not every son born in his kingdom, for this would have ruined it in time; but that was born to the Jews, as the Targums of Onkelos and Jonathan; and it is added in the Septuagint version, to the Hebrews:

and every daughter you shall save alive ;
for the reasons given (See Gill on Exodus 1:16).