וַתֹּ֕אמֶר הִנֵּ֛ה אֲמָתִ֥י בִלְהָ֖ה בֹּ֣א אֵלֶ֑יהָ וְתֵלֵד֙ עַל־בִּרְכַּ֔י וְאִבָּנֶ֥ה גַם־אָנֹכִ֖י מִמֶּֽנָּה׃
And she said: ‘Behold my maid Bilhah, go in unto her; that she may bear upon my knees, and I also may be builded up through her.’
Read halakhic rulings (Jewish law) on Genesis 30:3: and classical halakhic sources.