Background and Context:
Abiathar was a significant priestly figure during the reigns of King Saul and King David. He was the son of Ahimelech, the high priest at Nob, and a descendant of Eli, the priest of Shiloh. Abiathar's escape to David marks a pivotal moment in the biblical narrative, highlighting the transition of priestly support from Saul to David.

Biblical Account:
The account of Abiathar's escape is primarily found in 1 Samuel 22. King Saul, in his paranoia and fear of losing the throne, accused the priests of Nob of conspiring with David. Saul ordered the massacre of the priests, carried out by Doeg the Edomite, resulting in the death of Ahimelech and other priests. Abiathar, however, managed to escape the slaughter.

1 Samuel 22:20-23 :
"But one son of Ahimelech son of Ahitub escaped and fled to David. His name was Abiathar, and he told David that Saul had killed the priests of the LORD. Then David said to Abiathar, 'I knew on that day when Doeg the Edomite was there that he would surely tell Saul. I am responsible for the lives of your whole family. Stay with me; do not be afraid, for he who seeks your life seeks mine. You will be safe with me.'"

Significance:
Abiathar's escape to David is significant for several reasons:

1. Priestly Support for David: Abiathar's alignment with David symbolized the transfer of divine favor and priestly support from Saul to David. As a priest, Abiathar brought with him the ephod, a priestly garment used for seeking God's guidance, which became an essential tool for David.

2. Survival of the Priestly Line: Abiathar's escape ensured the survival of the priestly line of Eli, fulfilling the prophecy that Eli's house would not be entirely cut off (1 Samuel 2:33).

3. Role in David's Reign: Abiathar served as a priest during David's reign and was a key religious figure. He, along with Zadok, supported David during Absalom's rebellion (2 Samuel 15:24-29).

4. Symbol of Loyalty and Protection: David's acceptance and protection of Abiathar demonstrated his commitment to justice and loyalty to those wronged by Saul's tyranny. David's assurance to Abiathar, "You will be safe with me," underscored the mutual trust and alliance between them.

Later Developments:
Abiathar's account continues into the reign of Solomon, where he initially supported Adonijah's claim to the throne. However, after Solomon's ascension, Abiathar was removed from the priesthood, fulfilling the prophecy against Eli's house (1 Kings 2:26-27).

Conclusion:
Abiathar's escape to David is a critical event that underscores the shifting dynamics of power and divine favor in Israel's history. His presence with David not only provided spiritual guidance but also reinforced David's legitimacy as the future king of Israel.