The words ‘guru’ and ‘goru’ sound only a little different. The guru sees to the happiness of the shishya (disciple) and the goru (cattle) are only connected with nourishment and comfort. If the guru sets a relationship to collect food, clothing and financial gifts from disciples, not making effort to dispel their defects and cannot offer any prospect of their salvation, they are not students of a guru, they are really goru (cattle). Certainly students should make arrangements for the fodder and water of one's own gurus, then certainly you will have to act, it is not bad to make arrangement for food and clothing: but one should receive one's own happiness from the way of a guru with all signs of knowledge. You should investigate the signs of an accomplished guru.
In the Shastra it is written that there are two marks of a guru: stotriyata (one who has thoroughly studied the Vedas) and brahmanishthata (one possessing knowledge of the immortal Self, Brahman).
The kind of guru that has only studied the Vedas, then to the doubts of the student he only guesses at the answers, but cannot be very precise; because he does not have the knowledge of the truth. Therefore the fruitful guru is one who gives very precise answers to the doubts of the students, the guessing is at an end, this may be the best mark of knowledge. Therefore it has been said that the two principal signs of a guru are shrotriyata (one who has thoroughly studied the Vedas) and brahmansihthata (one possessing knowledge of the immortal Self).
Swami Brahmanand Saraswati
(Source: ‘Amrita Kanna’ of Brahmanand Saraswati translated by Paul Mason.)
Swami Brahmanand Saraswati, the Shankaracharya of Jyotirmath, was the guru of Maharishi Mahesh Yogi.