In Genesis (6:19) God commands Noah to gather the animals:
וּמִכָּל־הָ֠חַי מִֽכָּל־בָּשָׂ֞ר שְׁנַ֧יִם מִכֹּ֛ל תָּבִ֥יא אֶל־הַתֵּבָ֖ה לְהַחֲיֹ֣ת אִתָּ֑ךְ
Verse 20, however, concludes that the animals would come:
מֵהָע֣וֹף לְמִינֵ֗הוּ וּמִן־הַבְּהֵמָה֙ לְמִינָ֔הּ מִכֹּ֛ל רֶ֥מֶשׂ הָֽאֲדָמָ֖ה לְמִינֵ֑הוּ שְׁנַ֧יִם מִכֹּ֛ל יָבֹ֥אוּ אֵלֶ֖יךָ לְהַֽחֲיֽוֹת
Again in the next chapter (7:2) we find the commandment for Noah to bring animals:
מִכֹּ֣ל ׀ הַבְּהֵמָ֣ה הַטְּהוֹרָ֗ה תִּֽקַּח־לְךָ֛ שִׁבְעָ֥ה שִׁבְעָ֖ה אִ֣ישׁ וְאִשְׁתּ֑וֹ
Then we find again in (7:9) that the animals came:
שְׁנַ֨יִם שְׁנַ֜יִם בָּ֧אוּ אֶל־נֹ֛חַ אֶל־הַתֵּבָ֖ה זָכָ֣ר וּנְקֵבָ֑ה כַּֽאֲשֶׁ֛ר צִוָּ֥ה אֱלֹהִ֖ים אֶת־נֹֽחַ
Nevertheless, the verse concludes "as God commanded Noah." One would assume that this means that he was commanded to do something. If they came of their own accord, then even had he been informed by God, it ought to have said "As God told Noah."
What is the resolution. Are the statements about them coming really just a way of saying that they were brought by Noah?
What do other Rishonim say about this?