Charles H. Spurgeon on Psalms 114:4

The mountains skipped like rams, and the little hills like lambs. At the coming of the Lord to Mount Sinai, the hills moved; either leaping for joy in the presence of their Creator like young lambs; or, if you will, springing from their places in affright at the terrible majesty of Jehovah, and flying like a flock of sheep when alarmed. Men fear the mountains, but the mountains tremble before the Lord. Sheep and lambs move lightly in the meadows; but the hills, which we are wont to call eternal, were as readily made to move as the most active creatures. Rams in their strength, and lambs in their play, are not more stirred than were the solid hills when Jehovah marched by. Nothing is immovable but God himself: the mountains shall depart, and the hills be removed, but the covenant of his grace abideth fast for ever and ever. Even thus do mountains of sin and hills of trouble move when the Lord comes forth to lead his people to their eternal Canaan. Let us never fear, but rather let our faith say unto this mountain, "Be thou removed hence and cast into the sea, "and it shall be done.