We say in the Amidah for Shabbos and Yom Tov, “Vetaheir libeinu le’avekha be’emes”, usually translated simply as “And purify our hearts to serve You in truth.”"Vetaheir libeinu” provides an interesting contrast to “veyacheid levaveinu li’ahavah ulyir’ah es shemekha — and unify our hearts to love and be in awe of Your name”, said in the last berakhah before the morning recitation of Shema. Libeinu stands distinct from levaveinu, the same two-veis “levav” that we find in Shema, “And you shall love Hashem your G-d bekhol levavekha, with all your heart.” There, Chazal interpret the word as “beshnei yitzrekha — with both your inclinations”. In “veyacheid levaveinu” we speak of unifying the warring urges of a complex heart, which notably has one veis for each inclination, “le