Charak Samhita
ग्रीष्मवर्ज्येषु कालेषु दिवास्वप्नात् प्रकुप्यतः। श्लेष्मपित्ते दिवास्वप्नस्तस्मात्तेषु न शस्यते ॥४४॥
॥ Consequences of improper daytime sleep॥ Sleeping during daytime is contraindicated in the seasons other than summer because it causes vitiation of kapha and pitta.
english translation
grISmavarjyeSu kAleSu divAsvapnAt prakupyataH। zleSmapitte divAsvapnastasmAtteSu na zasyate ॥44॥
hk transliteration by Sanscript