A.T. Robertson Commentary Philippians 4:6

"In nothing be anxious; but in everything by prayer and supplication with thanksgiving let your requests be made known unto God." — Philippians 4:6 (ASV)

In nothing be anxious (μηδεν μεριμνατε). Present imperative in prohibition, "stop being anxious." See μη μεριμνατε in Mt 6:31.

With thanksgiving (μετα ευχαριστιας). In all the forms of prayer here named thanksgiving should appear.