This rascal Prahlāda has appeared like a thorn tree in a forest of sandalwood. To cut down sandalwood trees, an axe is needed, and the wood of the thorn tree is very suitable for the handle of such an axe. Lord Viṣṇu is the axe for cutting down the sandalwood forest of the family of demons, and this Prahlāda is the handle for that axe.
Srimad Bhagavata Purana
श्रीमद्भागवतमहापुराणम्
मूल श्लोकः
दैतेयचन्दनवने जातोऽयं कण्टकद्रुमः । यन्मूलोन्मूलपरशोर्विष्णोर्नालायितोऽर्भकः
daiteyacandanavane jāto'yaṃ kaṇṭakadrumaḥ | yanmūlonmūlaparaśorviṣṇornālāyito'rbhakaḥ
SB 7.5.17