How did Yehonason strengthen David 'bEi'lokim'?
Rashi: He renewed the Bris between them.
Radak based on Targum Yonasan: He assured him not to worry about Elokim's word via the Navi that David will reign; Sha'ul will not find him.
Malbim: He assured him not to worry, for Elokim is with him; His Hashgachah will save him from every side. He also assured him (a) Sha'ul will not find him, for he does not know where David is; (b) You will reign, and your horn will be lifted in the merit of the Rabim, for this is the sunrise of your success. My father's house will be under you; (c) Also Sha'ul knows this, and he fears to do anything to you. 1
We find that Sha'ul was optimistic of catching David (verses 21-23)! Malbim (verse 19) explains that his mindset changed after Zifim told him where David is.
