וַיְשַׁלַּ֥ח אֶת־הַיּוֹנָ֖ה מֵאִתּ֑וֹ לִרְאוֹת֙ הֲקַ֣לּוּ הַמַּ֔יִם מֵעַ֖ל פְּנֵ֥י הָֽאֲדָמָֽה׃
And he sent forth a dove from him, to see if the waters were abated from off the face of the ground.
Rashi on Genesis
וישלח את היונה AND HE SENT FORTH A DOVE at the end of seven days, for it is written, (Genesis 8:10) “And he stayed yet other seven days” — from this statement you may infer that after the first occasion, also, he waited seven days.
Sforno on Genesis
וישלח את היונה, all of the seven pairs of pigeons [based on the latter ה in front of the word יונה. Ed.]