Munisuttaṃ

Sikhī yathā nīlagīvo vihaṅgamo, 

haṃsassa nopeti javaṃ kudācanaṃ;

Evaṃ gihī nānukaroti bhikkhuno, 

munino vivittassa vanamhi jhāyatoti. 
(Munisuttaṃ, Uragavagga, Suttanipāta)

The flying peacock having a greenish-blue neck never attains the swiftness of the swan. Similarly, a householder cannot match a bhikkhu who meditates in the forest free from all attachments.