In the Ṛgveda (Rigveda), Ṛiṣti (Rishti) was mentioned as the name of a sharp weapon-

Vāśīmantaḥ ṛṣtimanto maṇīṣiṇaḥ.

This concept becomes more clear in the line- He throws the lightening like Ṛiṣti (Rishti)-

Ārukmairāyudhā nara ṛṣvā, ṛṣtīrasṛkṣata.

In this mantra, Sāyanāchārya gives the meaning of the word Ṛiṣti (Rishti) as ‘āyudha’- ṛṣtīrāyudha (rishtirayudha) as an adjective.

Ṛiṣti (Rishti) also means a kind of wooden stick. Nīlakaṇtha (Nilakantha) gives this meaning in his commentary-

Rṣtayo daṇḍāḥ.

In the Vanaparva, Kṛṣṇa (Krishna) described the war with Soubhapati Śālva (Salva) to the Pāṇḍava (Pandava). While he was narrating the weapons which were used by the army of the king Śālva (Salva) in the war, he mentioned Asi or sword, Śakti (Sakti), Kuliśa (Kulisa), Pāśa (Pasa) and Ṛiṣti (Rishti) in the plural. Again in the Udyogaparva, Duryodhana divided the army into different groups. Each group of soldiers was created according to the weapon they used in the war. For example, the group of soldiers who would use Tomara in the war, was named ‘Satomarāḥ’ (Satomarah). The group of soldiers who would fight with Śūla or Bhindipāla (Sula or Vindipala), they would be named ‘Saśūlabhindipālāśca’ (Sasulabhindipalascha). Similarly, the soldiers who would use Ṛṣti (Rishti) in the war, would be clubbed as -‘Saharṣtayaḥ’ (Saharshtayah). So the commentator Nīlakaṇtha (Nilakantha) makes it clear that Ṛṣti (Rishti) is a very heavy stick made of strong wood-
Ṛṣtirgurutaraḥ kāṣthadaṇḍaḥ.

In reference to another śloka (sloka) in the Mahābhārata (Mahabharata), some of the scholars describe Ṛṣti (Rishti) as a sword with a double sided sharpness In other words, it is called Asi. After winning over Droupadī (Droupadi) in the Svayaṇvara- sabhā (Svayanvara- sabha or the special court where the woman has the right to choose her husband), Drupada invited the Pāṇḍavas (Pandavas) in the royal court. To understand the kṣatriyatva (kshatriyatva or the quality of a warrior) of the unknown Pāṇḍavas (Pandavas), Drupada displayed various types of weapons before them. Among these weapons, Ṛṣti (Rishti) was placed besides the Śakti (Sakti) weapon.

In the Bhāgvata Purāṇa (Bhagavata Purana), Ṛṣti (Rishti)  as a weapon was mentioned along with Śakti (Sakti) and Cakra (Chakra or wheel) while discussing the event of cutting the head of the enemy (Śrāṁsi cicchiddhaḥ).  It proves that Ṛṣti (Rishti) can be considered as a sharp weapon like a sword. This idea becomes true in Amarkoṣa (Amarkosha) as it accepts both the words-Ṛṣti (Rishti) and Asi as synonymous with the word Khaḍga –

Khaḍge tu nistriṁśa- candrahāsāsiriṣṭayaḥ.

Though in the Amarkoṣa (Amarkosha), it is read as Riṣti (Rishti), all the commentators called it ‘Ṛṣti (Rishti)’ and this weapon is as sharp as Asi or sword. Another ancient koṣa (kosha or encyclopedia) directly comments that Ṛṣti (Rishti) is khaḍga (kharga) and taravāri (taravari or sword)-

Ṛṣtiḥ khaḍgastaravāriḥ.