וְהִ֖יא מָ֣רַת נָ֑פֶשׁ וַתִּתְפַּלֵּ֥ל עַל־יְהוָ֖ה וּבָכֹ֥ה תִבְכֶּֽה׃
и она была в горечи души—и молился Господу, и плакал от боли.
Radak
So she prayed upon (al) the Lord: It is like, to (el) the Lord. Likewise (Isaiah 29:11-12), "And he gave the book upon someone who [...] knows books," is like, to someone; (II Kings 22:8) "upon Shafan," is like to Shafan.
Metzudat David
And she was bitter in spirit: When she came to pray, her spirit was very bitter.