But I am like a green olive-tree in the house of God - I shall be in the house of God, full of spiritual vigor, bringing forth evergreen leaves and annual fruit, as the olive does when planted in a proper soil and good situation. It does not mean that there were olive-trees planted in God's house; but he was in God's house, as the olive was in its proper place and soil.
I trust in the mercy of God - The wicked man trusts in his riches: I trust in my God. He, like a bad tree, bringing forth poisonous fruit, shall be cursed, and pulled up from the roots; I, like a healthy olive in a good soil, shall, under the influence of God's mercy, bring forth fruit to his glory. As the olive is ever green, so shall I flourish in the mercy of God for ever and ever.
But I am like a green olive-tree in the house of God - I am safe and happy, notwithstanding the effort made by my enemy, the informer, to secure my destruction. I have been kept unharmed, like a green and flourishing tree - a tree protected in the very courts of the sanctuary - safe under the care and the eye of God. A green tree is the emblem of prosperity. See Psalm 1:3, note; Psalm 37:35, note; compare Psalm 92:12. The “house of God” here referred to is the tabernacle, considered as the place where God was supposed to reside. See Psalm 15:1, note; Psalm 23:6, note; Psalm 27:4-5, notes. The particular allusion here is to the “courts” of the tabernacle. An olive tree would not be cultivated in the tabernacle, but it might in the “courts” or “area” which surrounded it. The name “house of God” would be given to the whole area, as it was afterward to the entire area in which the temple was. A tree thus planted in the very courts of the sanctuary would be regarded as sacred, and would be safe as long as the tabernacle itself was safe, for it would be, as it were, directly under the divine protection. So David had been, notwithstanding all the efforts of his enemies to destroy him.
I trust in the mercy of God forever and ever -
(a) I “have” always done it. It has been my constant practice in trouble or danger.
(b) I “will” always do it.
As the result of all my experience, I will still do it; and thus trusting in God, I shall have the consciousness of safety.