Bhagavad Gita Chapter 15, Verse 3

न रूपमस्येह तथोपलभ्यते नान्तो न चादिर्न च सम्प्रतिष्ठा | अश्वत्थमेनं सुविरूढमूलमसङ्गशस्त्रेण दृढेन छित्त्वा ||

na rūpam asyeha tathopalabhyate nānto na cādir na ca sampratiṣṭhā aśvattham enaṁ suvirūḍha-mūlam asaṅga-śastreṇa dṛḍhena chittvā

The real form of this tree cannot be perceived here, nor its end, nor its beginning, nor its foundation. Having cut this firmly rooted banyan tree with the strong weapon of non-attachment...

Krishna reveals the tree's true nature: 'Na rūpam asyeha tathopalabhyate'—its real form cannot be perceived here in the material world. 'Nānto na cādiḥ na ca sampratiṣṭhā'—it has no end, no beginning, no foundation. This is the eternal cycle—you can't see where it started or where it ends because it's been going on forever. But here's the solution: 'Aśvattham enaṁ suvirūḍha-mūlam asaṅga-śastreṇa dṛḍhena chittvā'—cut this firmly rooted tree with the strong weapon of non-attachment. The tree is 'suvirūḍha-mūlam'—deeply rooted, entrenched. You can't just pull it out—you need a weapon. The weapon is 'asaṅga-śastreṇa'—non-attachment. Not just mild detachment, but 'dṛḍhena'—firm, resolute non-attachment. This is the axe that cuts the tree. You must cut it decisively, not tentatively. The tree of material existence is so deeply rooted in your consciousness that only firm, resolute detachment can cut it. Once cut, you find what the next verse reveals—the Supreme abode.