Rashi on I Samuel
One choice portion. One choice portion which is fit to be accepted with a friendly countenance.10אַפָּיִם referring to the face rather than to the portion. Ralbag renders “a double sized portion.”
Metzudat David on I Samuel
One portion: Meaning to say, unique in its fineness. And to explain further, it said, "apayim (face)" - one fitting to be received with a joyful face.
Radak on I Samuel
But to Hannah he would give (lit., he will give): It is like, he gave - like (other examples of the future tense indicating the past), "Then Yehoshua will build" (Joshua 8:30); "Then Moshe will separate" (Deuteronomy 4:41).