אִם־לֹ֤א שִׁוִּ֨יתִי ׀ וְדוֹמַ֗מְתִּי נַ֫פְשִׁ֥י כְּ֭גָמֻל עֲלֵ֣י אִמּ֑וֹ כַּגָּמֻ֖ל עָלַ֣י נַפְשִֽׁי׃
Rashi on Psalms
I calmed and quieted my soul upon You, like a suckling who is placed upon his mother. גָמוּל is one who sucks the breasts.
Rashi on Psalms
like a suckling was my soul with me My soul within me was before You as an infant sucking its mother’s breasts.