Poison- anabhyase visham vidyaa- Sanskrit sloka

when not practiced, knowledge is poison; in indigestion, food is poison |
poison is gathering/festivities of poor; old man's young wife is poison ||

अनभ्यासे विषं विद्या अजीर्णे भोजनं विषम् ।
विषं सभा दरिद्रस्य वृद्धस्य तरुणी विषम् ॥