Judges 14:1–20 and Judges 15:1–20 share several similarities:
Both begin with Samson’s speaking with a disagreeable father about a wife (Judges 14:1–3; Judges 15:1–3).
Both show Samson’s power over wild animals (Judges 14:5–9; Judges 14:5–9).
Both mention the Philistines’ ruling over Israel (Judges 14:4; Judges 15:11).
Both show the Spirit rushing upon Samson immediately after an opponent comes roaring/shouting to meet him (Judges 14:5–6; Judges 15:14).1
1 Samson went down to Timnah, and at Timnah he saw one of the daughters of the Philistines.