Those who grasp at precepts not established by the Buddha, which cannot bring liberation, cannot be liberated from birth and death.

Original text of the Laṅkāvatāra Sūtra:大慧。戒取者云何。须陀洹不取戒。谓善见受生处苦相故。是故不取。大慧。取者谓愚夫。决定受习苦行。为众具乐。故求受生。彼则不取。除回向自觉胜。离妄想。无漏法相行方便。受持戒支。是名须陀洹取戒相断。

Explanation: The Buddha said, "Mahāmati, what does the grasping of precepts mean? A srotāpanna does not grasp non-precepts and does not hold precepts that cannot lead to liberation. Because a srotāpanna is skilled at observing the marks of the painful retribution and painful fruits of holding precepts that are not in accordance with reason, which cannot liberate one from birth and death, therefore he does not grasp non-precepts and does not hold precepts contrary to reason. Mahāmati, those who grasp non-precepts not established by the Buddha that cannot lead to liberation are ignorant ordinary beings; they will certainly accept and practice asceticism, and their purpose is to obtain the various pleasures of the world, and so they will undergo rebirth again."

But a srotāpanna will not grasp non-precepts, unless he turns his mind toward the path to buddhahood, has already departed from deluded views, has eradicated afflictions in his mind-ground and reached the untainted state, and, as an expedient means to gather in and guide sentient beings, he manifests in accordance with conditions the appearance of holding non-Buddhist precepts. This shows that a srotāpanna has eradicated the grasping of precepts.