Sundardas (1596-1689) was a disciple of Dadu Dayal, and perhaps the best known of the early Dadu-panth.
He was sent to live in Dadu's household at the age of six. Although Dadu died soon after, he most probably gave realisation to the young child before his death.
Sundardas clearly experienced Sahaja:
Rare is the person who feels thirsty for drinking the juice of meditation on the name 'Rama'.
We then become the residents of the supreme region which is at the top of the brain.
There exists the lake of ambrosial juice.
As for the ambrosial juice it is exceedingly dear, though it can be available throughout the year.
One who drinks that becomes immortal.
Even kings like Bharthari have totally left to enjoy the kingly pleasure;
and after besmearing the body with ashes have become unconcerned like Goraknatha and Kabira.
Sundardasa says that he too was benefitted spiritually by the grace of his Guru, Dadu Dayal
In one song Sundardas recorded his Sahaja lineage:
That perfectly pure Sahaja is in everything and with that Sahaja all religious people gather together.
Sankara began his sadhana in this Sahaja,
Sukdeva, Sanaka and others also followed this Sahaja way.
Devotees like Soja, Pipa, Sena and Dhana all have drunk of this Sahaja-bliss in the natural way.
Raidas was also a sadhaka of Sahaja, and Guru Dadu also realised infinite bliss in this Sahaja path.