The Guru and his men were given a warm welcome at Dacca. People came from all over to pay homage to him. Everyday, more and more disciples came into his fold. The Guru won the adoring admiration of the viceroy, Shaista Khan, who still kept many Hindus in his administration, in highly respectable positions. He preached that only by the renunciation of all desires can a man achieve happiness. He told them that attachments and pursuits of pleasure only bring grief and misery into life.
Guru Tegh Bahadur was still at Dacca when he received the news of the birth of his son, Gobind, On December 26, 1666, by a messenger who had come all the way from Patna. There was great rejoicing in his camp and in all the sangats when they heard the good news. There were large - scale celebrations, and food and clothes were distributed among the poor. he now wanted to proceed further, and spread the message of God in the interiors of Bengal. He wished to cover all the places from Rajmahal in the west to Sylhet in the east, and from Dhubri in the south. When he decided to leave Dacca, the people became very sad and begged him to stay, but Guru Tegh Bahadur said that it was the will of God that he leave and spread the name everywhere.
In 1667, Guru Tegh Bahadur and his entourage left Dacca with Raja Ram Rai. They reached Sylhet in a couple of days, where he preached to the people, and infused a new spirit into them. The name of Akal Purukh reverberated from all directions.
From Sylhet they proceeded further towards Sondip, passing through Shaistaganj, Agartala and Chittagong. In Chittagong he established a sangat, and made many more disciples. After visiting several other places in Assam he return to Dacca early, in the year 1668. He was sad to find that the people here had again lost all hopes due to the ever increasing Mughal tyranny. They were very upset and gloomy about the future. Guruji exhorted them to worship one God, fear no one, and to remain united. He succeeded in raising their spirits and infusing courage and strength in them.
The political scene was undergoing tremendous change at that time. The Mughal Emperor was hungry for the extension of his empire, and wanted to convert the whole of India into Dar-ul-Islam. In December 1667, when he heard that Guwahati was attacked by the Ahoms, he was furious. He cleverly reinstated Raja Ram Singh as the General of his army, and ordered him to attack the Ahoms.
In Dacca, Raja Ram went to meet Guru Tegh Bahadur, and sought his protection. Guruji not only agreed to protect him but also assured that he would accompany him to Kamrup since he wanted to spread the name in every corner of the area. In December 1668, Guru Tegh Bahadur and Raja Ram Singh left for Assam. On the way, the Guru preached at several places. When they reached Assam the Guru suggested that the dispute of the Assamese with the Imperial army should be settled by negotiations rather than by war, as war would bring about only destruction and bloodshed. As a result of his advice, The Assamese sent a conciliatory message which was reciprocated by Raja Ram Singh, at the insistence of Guru Tegh Bahadur. Thus by his efforts, a serious conflict between the two armies was averted.
The Guru then left Assam for Patna in February 1670. The news of his arrival in Patna sent waves of joy everywhere, and people were ecstatic at having their Guru back. The Guru too, was delighted to see his son, Gobind Singh, growing strong, both in body and spirit. Guruji thanked to Patna Sangat for looking after his family so well. Guruji stayed in Patna for sometime. Then he set out for Punjab passing through Jaunpur, Ayodhya, Lucknow and Moradabad. The Guru gave Namdan to the people gathered there for his darshan.