Krishna now begins the threefold classification. First, the lowest: tamasic tyaga. He says that giving up your prescribed duties — the responsibilities that life naturally places before you — is not appropriate. When someone abandons these duties out of delusion, that abandonment is tamasic.
What does this look like in practice? A parent who stops caring for their children because they feel overwhelmed. A worker who quits every job when it gets hard, not because of principle but because of fatigue and confusion. The duties are real. The abandonment comes from fog in the mind, not from wisdom.
The Gita does not mince words here. Tamasic tyaga is renunciation driven by moha — a clouded understanding that mistakes laziness for liberation.