The passage below is from Sarkutavali written by Pandit Hardyal Ji, who is from the lineage of a famous Manjidhar, Pandit Beni Prashaad, a Sikh of Guru Amar Das Ji. Pandit Hardyal Ji completed Sarkutavali in 1833, but also wrote Vairaag Shatak . These two scriptures have been standard in the curriculum for various Sampradayas and Taksals since their composition. Even today the famous Damdami Taksal still requires their students to read these texts during their schooling, and of course this tradition is continued by Nirmalas, Seva Panthis and Udasis. The following passage describes the good and bad that can arise from studying scriptural knowledge, also describing that the reading of such knowledge be restricted to those worthy and deserving [through action/merit not birthright]. The criteria for which one to decipher whether a student is worthy or not is described in detail further in the text but is not included in this post.
ਸ੍ਵੈਯਾ । ਇਹ ਵੇਦ ਕੋ ਗ੍ਯਾਨ ਸੁਜਾਨਨ ਕੇ ਅਭਿਮਾਨ ਮਦਾਦਿ ਵਿਕਾਰ ਵਿਨਾਸੇ ।
[Reading and understanding] scriptural knowledge the intelligent ones destroy their ego and evil tendencies.
ਪੁਨ ਕੇਚਿਤ ਨੀਚਨ ਕੋ ਵਹੁ ਬੋਧ ਮਦੈ ਅਭਿਮਾਨ ਵਿਕਾਰ ਨਿਵਾਸੇ ।
However reading those same scriptures the foolish ones only enshrine ego and [other] vices within their heart.
ਅਚ ਅੰਮ੍ਰਿਤ ਜਾਸ ਹਲਾਹਲ ਹ੍ਵੈ ਨਹਿ ਔਖਧ ਵੈਦ ਨਹੀ ਕੁਛ ਤਾਸੇ ।
Just as if one drinks Amrit which then turns to poison, there can be no doctor that can cure them.
ਜਨ ਪਾਤ੍ਰ ਕੁਪਾਤ੍ਰ ਕੋ ਸੋਧਿ ਕੈ ਬੋਧ ਕਰੈ ਬੁਧਿਵਾਨ ਜੋ ਬੋਧ ਪ੍ਰਕਾਸੇ ।2।
An intelligent [teacher] is one who tests [their students] understanding who is deserving or not of [scriptural] knowledge.
ਦੋਹਰਾ ।ਸਾਸਤ੍ਰ ਕਰਿ ਮਤ ਹਤ ਸੁਜਨ ਖਲ ਕੋ ਮਦ ਉਪਜੰਤ ।
Reading scriptural knowledge, the intelligent one eliminates his ego, whereas the fool [only] increases his ego.
ਜ੍ਯੋਂ ਦ੍ਰਿਗ ਭਾਨੁ ਪ੍ਰਕਾਸ਼ ਹ੍ਵੈ ਉਲੂ ਅੰਧ ਕਰੰਤ ।27।
Just like the rising of the sun illuminates [the world], it also can blind the owl.