The eternal God is thy refuge, and underneath are the everlasting arms: and he shall thrust out the enemy from before thee; and shall say, Destroy them.

Wesley's Notes

33:27 The eternal God - He who was before all worlds, and will be, when time shall be no more: Is thy refuge - Or, thy habitation or mansion - house (so the word signifies) in whom thou art safe, and easy, and at rest, as a man is in his own house. Every true Israelite is at home in God: the soul returns to him, and reposes in him. And they that make him their habitation shall have all the comforts and benefits of an habitation in him. And underneath are the everlasting arms - The almighty power of God, which protects and comforts all that trust in him, in their greatest straits and distresses. He shall thrust out the enemy from before thee - Shall make room for thee by his resistless power, and shall say, Destroy them - Giving thee not only a commission but strength to put it in execution. And, has he not given the same commission and the same strength to believers, to destroy all sin?

Matthew Henry's Concise Commentary

33:26-29 None had such a God as Israel. There is no people like the Israel of God. What is here said of the church of Israel is to be applied to the spiritual church. Never were people so well seated and sheltered. Those who make God their habitation, shall have all the comforts and benefits of a habitation in him, Ps 91:1. Never were people so well supported and borne up. How low soever the people of God are at any time brought, everlasting arms are underneath them, to keep the spirit from sinking, from fainting, and their faith from failing. Divine grace is sufficient for them, 2Co 12:9. Never were people so well commanded. Thus believers are more than conquerors over their spiritual enemies, through Christ that loved them. Never were people so well secured and protected. Israel shall dwell in safety alone. All who keep close to God, shall be kept safe by him. Never were people so well provided for. Every true Israelite looks with faith to the better country, the heavenly Canaan, which is filled with better things than corn and wine. Never were people so well helped. If in danger of any harm, or in want of any good, they had an eternal God to go to. Nothing could hurt those whom God helped, nor was it possible the people should perish who were saved by the Lord. Never were people so well armed. Those in whose hearts is the excellency of holiness, are defended by the whole armour of God, Eph 6. Never were people so well assured of victory over their enemies. Thus shall the God of peace tread Satan under the feet of all believers, and shall do it shortly, Ro 16:20. May God help us to seek and to set our affections on the things above; and to turn our souls from earthly perishing objects; that we may not have our lot with Israel's foes in the regions of darkness and despair, but with the Israel of God, in the realms of love and eternal happiness.