SB 5.10.4
na vayam nara-deva pramatta bhavan-niyamanupathah sadhv eva vahamah. ayam adhunaiva niyukto ’pi na drutam vrajati nanena saha vodhum u ha vayam parayama iti.
Translation by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
O lord, please note that we are not at all negligent in discharging our duties. We have been faithfully carrying this palanquin according to your desire, but this man who has been recently engaged to work with us cannot walk very swiftly. Therefore we are not able to carry the palanquin with him.
Purport by His Divine Grace A. C. Bhaktivedanta Swami Srila Prabhupada:
The other palanquin carriers were sudras, whereas Jada Bharata was not only a high-caste brahmana but also a great devotee. Sudras do not sympathize with other living beings, but a Vaisnava cannot act like a sudra. Whenever a sudra and a brahmana Vaisnava are combined, there will certainly be imbalance in the execution of duties. The sudras were walking with the palanquin without at all caring for the ants on the ground, but Jada Bharata could not act like a sudra, and therefore difficulty arose.