Like some other psalms (e.g. Psalm 25:1–22) every sentence of this Psalm starts with a letter of the Hebrew alphabet. For example:
A A great God is Yahweh;
B Better than all other gods;
C C… and so on
The reason for this is to help others to learn the Psalm by heart, so that they can use it to praise the Lord and walk in the fear of him daily.
1 De David. Lorsqu'il contrefit l'insensé en présence d'Abimélec, et qu'il s'en alla chassé par lui.