MAH TOVU (Heb. מַה טֹּבוּ; "How goodly"), the opening words of a prayer recited by Ashkenazi Jews upon entering the synagogue. The initial words are a quotation from Numbers 24:5. The remainder of the prayer consists of Psalms 5:8; 26:8; 69:14; and 95:6 (with Ps. 95:6 modified from the plural to the singular form). The Talmud interprets the "tents" and "dwellings" of Numbers 24:5 to refer to synagogues and schools (Sanh. 105b), and the "time of grace" mentioned in Psalms 69:14, to mean the time of public worship (Ber. 8a). At one time, the rabbis apparently intended to include Balaam's blessing of the children of Israel (Num. 22–24) in the recitation of *Shema; however, they decided that it was too lengthy for the congregation (Ber. 12b).
Sephardi Jews recite Psalms 5:8 on entering the synagogue, and Psalms 5:9 on leaving.
Elbogen, Gottesdienst, 87, 526; Idelsohn, Liturgy, 73f.; E. Levy, Yesodot ha-Tefillah (19522), 76, 131.
"Mah Tovu." Encyclopaedia Judaica. . Encyclopedia.com. (September 18, 2018). http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/mah-tovu
"Mah Tovu." Encyclopaedia Judaica. . Retrieved September 18, 2018 from Encyclopedia.com: http://www.encyclopedia.com/religion/encyclopedias-almanacs-transcripts-and-maps/mah-tovu