וַתֹּ֣אמֶר לֵאָ֔ה בְּאָשְׁרִ֕י כִּ֥י אִשְּׁר֖וּנִי בָּנ֑וֹת וַתִּקְרָ֥א אֶת־שְׁמ֖וֹ אָשֵֽׁר׃
И Лия сказала: 'Я счастлив! потому что дочери назовут меня счастливым.' И она назвала его по имени Ашер.
Rashbam
באשרי, I am glowing in the praises and good wishes bestowed on me by the other women.
Radak
ותלד..ותאמר..באשרי, the root of the word is in the kal conjugation. She said that others will give me credit for building Yaakov’s future seeing that between her sons and her handmaids sons they had contributed 8 out of 12.
Sforno
באשרי, this son is part of my bliss, my happiness, because he is also a son for me.