The Ramayana/Book I/Canto LXI: S'unahs'epha
Then Vis'vámitra, when the Blest
Had sought their homes of heavenly rest,
Thus, mighty Prince, his counsel laid
Before the dwellers of the shade:
'The southern land where now we are
Offers this check our rites to bar: 
To other regions let us speed,
And ply our tasks from trouble freed.
Now turn we to the distant west.
To Pushkar's  wood where hermits rest,
And there to rites austere apply,
For not a grove with that can vie.'
The saint, in glory's light arrayed,
In Pushkar's wood his dwelling made,
And living there on roots and fruit
Did penance stern and resolute.
The king who filled Ayodhyá's throne,
By Ambarísha's name far known,
At that same time, it chanced, began
A sacrificial rite to plan.
But Indra took by force away
The charger that the king would slay.
The victim lost, the Bráhman sped
To Ambarísha's side, and said:
'Gone is the steed, O King, and this
Is due to thee, in care remiss.
Such heedless faults will kings destroy
Who fail to guard what they enjoy.
The flaw is desperate: we need
The charger, or a man to bleed.
Quick! bring a man if not the horse,
That so the rite may have its course.'
The glory of Ikshváku's line
Made offer of a thousand kine,
And sought to buy at lordly price
A victim for the sacrifice.
To many a distant land he drove,
To many a people, town, and grove,
And holy shades where hermits rest,
Pursuing still his eager quest.
At length on Bhrigu's sacred height
The saint Richika met his sight
Sitting beneath the holy boughs.
His children near him, and his spouse.
The mighty lord drew near, assayed
To win his grace, and reverence paid;
And then the sainted king addressed
The Bráhman saint with this request:
'Bought with a hundred thousand kine,
Give me, O Sage, a son of thine
To be a victim in the rite,
And thanks the favour shall requite.
For I have roamed all countries round,
Nor sacrificial victim found.
Then, gentle Hermit, deign to spare
One child amid the number there.'
Then to the monarch's speech replied
The hermit, penance-glorified:
'For countless kine, for hills of gold,
Mine eldest son shall ne'er be sold.'
But, when she heard the saint's reply,
The children's mother, standing nigh,
Words such as these in answer said
To Ambarisha, monarch dread:
'My lord, the saint, has spoken well:
His eldest child he will not sell.
And know, great Monarch, that above
Tht rest my youngest born I love.
'Tis ever thus: the father's joy
Is centred in his eldest boy.
The mother loves her darling best
Whom last she reeked upon her breast:
My youngest I will ne'er forsake.'
As thus the sire and mother spake,
Young S'unahs'epha, of the three
The midmost, cried unurged and free:
'My sire withholds his eldest son,
My mother keeps her youngest one:
Then take me with thee, King: I ween
The son is sold who comes between.'
The king with joy his home resought,
And took the prize his kine had bought.
He bade the youth his car ascend,
And hastened back the rites to end. 
- 'This cannot refer to the events just related: for Vis'vámitra was successful in the sacrifice performed for Tris'anku. And yet no other impediment is mentioned. Still his restless mind would not allow him to remain longer in the same spot. So the character of Vis'vámitra is ingeniously and skilfully shadowed forth: as he had been formerly a most warlike king, loving battle and glory, bold, active, sometimes unjust, and more frequently magnanimous, such also he always shows himself in his character of anchorite and ascetic.' SCHLEGEL.
- Near the modern city of Ajmere. The place is sacred still, and the name is preserved in the Hindí. Lassen, however, says that this Pushkala or Pushkara, called by the Grecian writers Πευκελἀίτις, the earliest place of pilgrimage mentioned by name, is not to be confounded with the modern Pushkara in Ajmere.
- Ambarisha is the twenty-ninth in descent from Ikshváku, and is therefore separated by an immense space of time from Tris'anku in whose story Vis'vámitra had played so important a part. Yet Richíka, who is represented as having young sons while Ambarísha was yet reigning, being himself the son of Bhrigu and to be numbered with the most ancient sages, is said to have married the younger sister of Vis'vámitra. But I need not again remark that there is a perpetual anachronism in Indian mythology.' SCHLEGEL.
'In the mythical story related in this and the following Canto we may discover, I think, some indication of the epoch at which the immolation of lower animals was substituted for human sacrifice....
So when Iphigenia was about to be sacrificed at Aulis, one legend tells us that a hind was substituted for the virgin.' GORRESIO.
So the ram caught in the thicket took the place of Isaac, or, as the Musalmáns say, of Ishmael.