Hallel of pesukei dezimra a selection of six psalms recited as part of pesukei dezimra ('verses of praise') – the introduction the daily morning service. This "Hallel" consists of Ashrei (most of which is Psalm 145) followed by Psalms 146–150. The term Hallel, without a qualifier, generally refers to Psalms 113-118, which are recited only on festivals; for this reason the Hallel of pesukei dezimra is also known as the daily Hallel.
These psalms are recited because they are devoted entirely to the praise of God.[1]
Originally, this was the only part of pesukei dezimra. Its recitation was considered voluntary for a long time.[1]