Charak Samhita
अष्टाभ्य एभ्यो हेतुभ्यः शुक्रं देहात् प्रसिच्यते। चरतो विश्वरूपस्य रूपद्रव्यं यदुच्यते ॥४९॥
the tendency to flow out and the speedy motion of vata. The un-manifested soul which takes different forms in this world, manifests itself in the form of semen.
english translation
aSTAbhya ebhyo hetubhyaH zukraM dehAt prasicyate। carato vizvarUpasya rUpadravyaM yaducyate ॥49॥
hk transliteration by Sanscript