Summary: Samson returned to his father-in-law’s house to take back his wife, only to be told that she had been given away to another man. Out of vengeance, he caught three hundred foxes, attached torches to their tails and let them loose in the fields of the Philistines to burn down their crops, causing a chain reaction of events.
A deeper look: Samson’s marriage to the woman from Timnat and her subsequent infidelity created the perfect excuse to take revenge against the Philistines. The Philistines blamed his wayward wife and her father for Samson’s anger towards their nation. They were burnt alive as punishment. This gave Samson the justification to launch his attack triggering a Philistine invasion of the Judean lands to arrest him. Fearing a full scale battle, the people of Judah bound Samson with ropes and handed him over. As the Philistines came to take him, he broke the ropes, picked up a donkey’s jawbone and used it to slay a thousand Philistine men.
Rabbi Yaakov Culi (d. 1732) explains that this jawbone was from the donkey of Bilaam. While Bilaam had ridden it in order to curse Israel, he had only been able to offer blessings. This is why Samson came across its jawbone now to kill the Philistines.
Rabbi Moshe Dovid Valle (d. 1777) explains the deeper significance of why specifically the jawbone of the donkey was used. Samson’s strength was not natural; it came on account of his relationship with God and could not be subdued by mere ropes or chains. We reinforce our connection to God through learning Torah using our own jaws by articulating the words with speech. Similarly Rashi (d. 1105) explains that the Jawbone was moist and so it reflected light, hinting again to the light of Torah.
Samson’s strength was needed to subdue his physical enemies. Our enemy is the yetzer hara – the inclination to indulge in activities which distance us from God. The Gemara explains that the antidote to this is learning Torah (Bava Basra 16a). This is how we can cultivate our spiritual strength and become mighty warriors in our own right.