Ashrei (Hebrew: אַשְׁרֵי) is a prayer that is recited at least three times daily in Jewish prayers, twice during Shacharit (morning service) and once during Mincha (afternoon service). The prayer is composed primarily of Psalm 145 in its entirety, with Psalms 84:5 and Psalms 144:15 added to the beginning, and Psalms 115:18 added to the end. The first two verses that are added both start with the Hebrew word ashrei (translating to 'happy is he who...', 'praiseworthy' or 'fortunate'), hence the prayer's name.[1]
The Talmud does not refer to the psalm by the (current) title of Ashrei, but rather as the opening words, Tehillah l'David.[2]