Shiva Purana

siva.sh/siva-purana/vishweshwara-samhita/18/90

शिष्यः पुत्र इति प्रोक्तः सदाशिष्यत्वयोगतः । जिह्वालिंगान्मंत्रशुक्रं कर्णयोनौ निषिच्यवै 1.18.९० ।

sanskrit

The disciple is called the son due to his eternal connection with the master. The sacred syllables (linga), mantras, and semen (energy) are to be placed in the mouth, ears, and other sacred places for purification and spiritual practice.

english translation

ziSyaH putra iti proktaH sadAziSyatvayogataH | jihvAliMgAnmaMtrazukraM karNayonau niSicyavai 1.18.90 |

hk transliteration by Sanscript